What type of mineral supplement should be used and how much should be fed?
Salt (NaCl) and a calcium-phosphorus mineral can be offered free-choice. However, it is best to adjust the kind and amount of minerals in the ration to the animal’s need. The amount of mineral to add to the ration depends on the following factors: • Type of forage in the diet. Legumes are rich in calcium and require less calcium supplementation than grasses. • The amount of concentrate in the diet. Usually, concentrates are low in minerals. Thus, the higher the amount of concentrates in a diet, the higher the need for mineral supplementation. • The mineral need of the cow. For maintenance, a cow needs 30 to 50 g of calcium and 10 to 30 g of phosphorus per day. Each kg of milk requires about 3 g of calcium and 2 g of phosphorus. When a ration is based on high and medium quality forages, a phosphorus mineral (e.g., monosodium phosphate) may be needed in the range of 0 to 150 g/cow/day. However, with low forage quality or with corn silage, both calcium and phosphorus will need to be suppl
